Fix for gift level check to be actually enabled first before we show the warning

[kimcoleman]

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Changes proposed in this Pull Request:

The warning was showing for all recurring levels - but this update fixes so it requires them to be "enabled" as a gift level before the recurring payment warning/notice shows.

Resolves #59.

Other information:

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Changelog entry

• BUG FIX: Resolved issue where the recurring payment warning was showing on all levels, not just gift levels.

Enter a summary of all changes on this Pull Request. This will appear in the changelog if accepted.